Year 10 Science · Unit 2 · Lesson 19

Evidence-Based Argumentation in Chemistry

Foundation Worksheet

Name

Date

Class

Learning Goals

Identify claim, evidence, and reasoning from a chemistry investigation write-up.
Match the CER framework components and source evaluation terms to their definitions.
Distinguish between scientific evidence and anecdote, opinion, or assumption.

Warm Up

Sort it!

A student wrote the following statements after a reaction rate investigation. Write each statement into the correct category box, Claim, Evidence, or Reasoning.

"Temperature affects reaction rate" "At 40°C the reaction took 29 seconds" "Faster particles collide more frequently and with more energy" "The reaction was faster at higher temperatures" "At 20°C the reaction took 95 seconds; at 60°C it took 11 seconds" "This supports collision theory" "As temperature increases, particles gain more kinetic energy" "Rate increased from 1.05 s⁻¹ to 9.09 s⁻¹ across the temperature range" "More collisions exceed the activation energy threshold, so more products form per second"

Claim

Evidence

Reasoning

Your Turn

Match each term to its correct definition

Draw a line connecting each term to its definition on the right. Or write the matching letter in the answer column.

Term	Your answer	Definition
Claim		A. The logical explanation of why your data supports your conclusion, using scientific theory
Evidence		B. A testable statement that directly answers the research question
Reasoning		C. Data, measurements, or observations that support or refute a claim
Peer review		D. When other scientists check a study before publication to confirm validity
Bias		E. A tendency to favour a particular outcome, often affecting how data is collected or reported
Anecdote		F. A personal story used as if it were scientific evidence, not reliable on its own

Show What You Know

1. A student says "Bleach and vinegar must be a powerful cleaner because they're both strong." Is this a claim, evidence, or reasoning? Explain what is missing from this student's scientific argument.

Recall 2 marks

2. A social media post says "Natural chemicals are always safe, they come from nature!" Give one example that shows this statement is incorrect, and explain why a natural origin does not determine whether a chemical is safe.

Recall 2 marks

Wrap Up

In one sentence, explain why a scientific argument needs all three parts of CER, not just a claim on its own.